pipewire/spa/lib/memory.c

/* Simple Plugin API
 * Copyright (C) 2016 Wim Taymans <wim.taymans@gmail.com>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 */

#include <stdio.h>

#include "spa/memory.h"

#define MAX_POOLS       16
#define MAX_MEMORIES    1024

struct _SpaMemoryPool {
  bool valid;
  uint32_t id;
  SpaMemory memories[MAX_MEMORIES];
  unsigned int n_free;
  uint32_t free_mem[MAX_MEMORIES];
};

static SpaMemoryPool pools[MAX_POOLS];

static void
spa_memory_pool_init (SpaMemoryPool *pool, uint32_t id)
{
  int i;

  for (i = 0; i < MAX_MEMORIES; i++)
    pool->free_mem[i] = MAX_MEMORIES - 1 - i;
  pool->n_free = MAX_MEMORIES;
  pool->id = id;
  pool->valid = true;
}

void
spa_memory_init (void)
{
  static bool initialized = false;

  if (!initialized) {
    spa_memory_pool_init (&pools[0], 0);
    initialized = true;
  }
}

uint32_t
spa_memory_pool_get (uint32_t type)
{
  return pools[type].id;
}

uint32_t
spa_memory_pool_new (void)
{
  int i;

  for (i = 0; i < MAX_POOLS; i++) {
    if (!pools[i].valid) {
      spa_memory_pool_init (&pools[i], i);
      return i;
    }
  }
  return SPA_ID_INVALID;
}

void
spa_memory_pool_free (uint32_t pool_id)
{
  pools[pool_id].valid = false;
}

SpaMemory *
spa_memory_alloc (uint32_t pool_id)
{
  SpaMemory *mem;
  SpaMemoryPool *pool;
  uint32_t id;

  if (pool_id >= MAX_POOLS || !pools[pool_id].valid)
    return NULL;

  pool = &pools[pool_id];

  if (pool->n_free == 0)
    return NULL;

  id = pool->free_mem[pool->n_free - 1];
  pool->n_free--;

  mem = &pool->memories[id];
  mem->refcount = 1;
  mem->pool_id = pool_id;
  mem->id = id;

  return mem;
}

SpaResult
spa_memory_free (uint32_t pool_id, uint32_t id)
{
  SpaMemoryPool *pool;

  if (pool_id >= MAX_POOLS || !pools[pool_id].valid)
    return SPA_RESULT_INVALID_ARGUMENTS;

  pool = &pools[pool_id];
  pool->free_mem[pool->n_free] = id;
  pool->n_free++;

  return SPA_RESULT_OK;
}

SpaMemory *
spa_memory_find (uint32_t pool_id, uint32_t id)
{
  SpaMemoryPool *pool;

  if (pool_id >= MAX_POOLS || !pools[pool_id].valid)
    return NULL;

  pool = &pools[pool_id];

  if (id >= MAX_MEMORIES || pool->memories[id].refcount <= 0)
    return NULL;

  return &pool->memories[id];
}